This regulation establishes tolerances for combined residues of the herbicide S-metolachlor and its metabolites in or on asparagus; carrot, roots; horseradish; onion, green; rhubarb; and swiss chard. The Interregional Research Project Number 4 (IR-4) requested these tolerances under the Federal Food, Drug, and Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act (FQPA) of 1996.